Three individual projects are proposed for the coming year. a) The horseradish peroxidase method will be employed to reveal the laminar origin and type of cells that project from area 18 upon area 17. b) Following the destruction of the lateral geniculate nucleus, degenerating axon terminals and their target cells in lamina VI of area 17 will be identified and classified. c) Following the injection of tritiated GABA in various cortical areas, we shall attempt to reveal the laminar distribution of cells that take up and retain GABA. Also, we plan to classify these "GABA-ergic" cells at the electron micrscopic level.